Present internal structures of the Earth and planets are the results of long-term deformation and fractionation of internal component materials since their births. To study internal structure leads us to know internal material properties and transport mechanisms. And, conversely, to study material properties and transport mechanisms takes us into understanding how present internal structures were created. In Earth and Planetary Physics Group we study internal structures, material properties and their transport mechanisms in the Earth and other planets from analyses of seismic waves, friction experiments, high-temperature and high-pressure experiments, and numerical simulations.